Having just brought a secondhand downpipe for my classic, I went to fit it to my car, only to find it doesn't mate up with my Mongoose exhaust. Oh bugger I thought, but as i looked at it a plan hatched that would allow me to fit the downpipe, but as I am going to have to modify it, why not go further and make it an open neck exhaust. Thanks to David Wallis for the insperation. Will post some photos later.

 

Heres the first picture of the downpipe being modified.



Luckily I have access to a workshop full of machinery and was able to mill the slot out to minimise distortion.

 

Make sure you leave enough clearance once welded for the nut and a spanner / socket..

David

 

Now its time to start welding the hole up, this was done using the existing piece of exhaust and new sheet metal





Been a while since i've done some welding so a little rusty.

 

This shows the other side of the exhaust, just need to fill the holes in now.



At last the top part is finished. No comments about the welding please.

 

The last thing to do is to make a boss for the exhaust to mate up with the mongoose system. The problem is on the original downpipe there is a boss that a wire gasket sits on, this is tapered and is bolted into the mongoose to provide a seal. The HKS downpipe doesn't have this flange. Ths solution, machine a reducer/adapter to fit inside the exhaust and provide a flange for the wire gasket





This just needs welding into the exhaust now.

 

Looks like you should stick to using the lathe

 

It looks better in real life........honest. Ermmm must be the way the light caught it.
You won't see it as it will be wrapped in exhaust wrap before it goes on the car.

 

nice reducer.


welding reminds me of the underside of a old B reg fiesta.

well done for posting it up though, good to see not all of us just "go out and buy one because we can afford it"

Andy

 

I know what you mean about welding and photos..

looking good..

David

 

Adapter is now welded into the downpipe.



Then the last thing to do is put the wire gasket on.



Now its ready to be fitted tonight

 

Downpipe all fitted, can't wait to take it for a spin, but the reason I changed the downpipe was because it was blowing, or thats what i thought, further investigation has shown that maybe the up pipe is blowing, its hard to see. looks like another weekend of exhaust removal/fitting

 

and turbo removal and refitting if the up pipe is split..!!

Dan